package lomasky.xui;

import android.content.Context;
import android.support.v7.widget.GridLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.view.View;
import android.view.ViewGroup;

public class WrapContentGridLayoutManager extends GridLayoutManager {

	private static final int DEFAULT_CHILD_SIZE = 100;

	private final int[] childDimensions = new int[2];

	private int childSize = DEFAULT_CHILD_SIZE;
	private boolean hasChildSize;



	private int   spanCount;
	public WrapContentGridLayoutManager(Context context, int spanCount) {
		super(context, spanCount);
		this.spanCount=spanCount;
	}




	private int[] mMeasuredDimension = new int[2];
	@Override
	public void onMeasure(RecyclerView.Recycler recycler, RecyclerView.State state, int widthSpec, int heightSpec) {
		final int widthMode = View.MeasureSpec.getMode(widthSpec);
		final int heightMode = View.MeasureSpec.getMode(heightSpec);
		final int widthSize = View.MeasureSpec.getSize(widthSpec);
		final int heightSize = View.MeasureSpec.getSize(heightSpec);
		int width = 0;
		int height = 0;

		//所有项除列数得到行数
		int lineCount=getItemCount()%spanCount==0?getItemCount()/spanCount:getItemCount()/spanCount+1;

//
		for (int i = 0; i <lineCount; i++) {

			try {
				measureScrapChild(recycler, i,
						widthSpec,
						View.MeasureSpec.makeMeasureSpec(i, View.MeasureSpec.UNSPECIFIED),
						mMeasuredDimension);
			} catch (IndexOutOfBoundsException e) {

				e.printStackTrace();
			}

			if (getOrientation() == HORIZONTAL) {
				width = width + mMeasuredDimension[0];
				if (i == 0) {
					height = mMeasuredDimension[1];
				}
			} else {
				height = height + mMeasuredDimension[1];
				if (i == 0) {
					width = mMeasuredDimension[0];

				}
			}
		}


		switch (widthMode) {
			case View.MeasureSpec.EXACTLY:
//                    width = widthSize;
			case View.MeasureSpec.AT_MOST:
			case View.MeasureSpec.UNSPECIFIED:
		}

		switch (heightMode) {
			case View.MeasureSpec.EXACTLY:
				height = heightSize;
			case View.MeasureSpec.AT_MOST:
			case View.MeasureSpec.UNSPECIFIED:
		}
		setMeasuredDimension(widthSpec, height);

	}

	private void measureScrapChild(RecyclerView.Recycler recycler, int position, int widthSpec, int heightSpec, int[] measuredDimension) {
		View view = recycler.getViewForPosition(position);


		if (view != null) {
			RecyclerView.LayoutParams p = (RecyclerView.LayoutParams) view.getLayoutParams();
			int childHeightSpec = ViewGroup.getChildMeasureSpec(heightSpec,
					getPaddingTop() + getPaddingBottom(), p.height);
			view.measure(widthSpec, childHeightSpec);
			measuredDimension[0] = view.getMeasuredWidth() + p.leftMargin + p.rightMargin;
			measuredDimension[1] = view.getMeasuredHeight() + p.bottomMargin + p.topMargin;
			recycler.recycleView(view);
		}
	}

	@Override
	public void onLayoutChildren(RecyclerView.Recycler recycler, RecyclerView.State state) {
//        Logger.e("SyLinearLayoutManager state:" + state.toString());
		super.onLayoutChildren(recycler, state);
	}


}